Subj : org.mozilla.javascript.EvaluatorException: Can't convert to type
To   : netscape.public.mozilla.jseng
From : mesuti@aciworldwide.com
Date : Wed Feb 25 2004 03:22 pm





Hi,

I want to use Rhino interpreter in a Smart Card Management system as ECMA
script interpreter. Rhino throws an exception when I call concat() method
of a Host Object that I implemented (ByteString). A part of the source code
can be seen below:



public class ByteString extends ScriptableObject {

    /** Creates a new instance of ByteString */
    public ByteString() {
    }

    public void jsConstructor(String s, Integer enc) {
       ...
    }

    public int jsGet_length() {
       ...
    }

    public ByteString jsFunction_concat(ByteString bs) throws IOException {
        ByteString bs1 = new ByteString();
        ...

        return bs1;
    }

    public String getClassName() {
        return "ByteString";
    }
}


Sample JavaScript  calling the concat method is also given below:

var tmpA  = new ByteString("Text1 ", ASCII);
var tmpB  = new ByteString("Text2", ASCII);
var tmpC  = tmpA.concat(tmpB); // this is the problem line


When Rhino evaluates the script it throws the following exception:

Evaluating JavScript D:\Data\Archive\Rhino-15R41\experiments\sample.js...
org.mozilla.javascript.EvaluatorException: Can't convert to type
"com.bla1.bla2.bla3.hostobjects.ByteString".
(D:\Data\Archive\Rhino-15R41\experiments\sample.js; line 3)
        at
org.mozilla.javascript.DefaultErrorReporter.runtimeError(DefaultErrorReporter.java:76)
        at
org.mozilla.javascript.Context.reportRuntimeError(Context.java:591)
        at
org.mozilla.javascript.Context.reportRuntimeError(Context.java:630)
        at
org.mozilla.javascript.Context.reportRuntimeError1(Context.java:606)
        at
org.mozilla.javascript.FunctionObject.convertArg(FunctionObject.java:359)
        at
org.mozilla.javascript.FunctionObject.call(FunctionObject.java:408)
        at
org.mozilla.javascript.ScriptRuntime.call(ScriptRuntime.java:1191)
        at
org.mozilla.javascript.gen.c1.call(D:\Data\Archive\Rhino-15R41\experiments\sample.js:3)
        at
org.mozilla.javascript.gen.c1.exec(D:\Data\Archive\Rhino-15R41\experiments\sample.js)
        at org.mozilla.javascript.Context.evaluateReader(Context.java:820)
        at
com.aciworldwide.scm.gp.JSInterpreter.<init>(JSInterpreter.java:64)
        at
com.aciworldwide.scm.gp.JSInterpreter.main(JSInterpreter.java:117)


It seems all methods with a "ByteString" argument causes the same problem.

Thanks

Ishak

.